The present invention pertains to a device for monitoring the health status of a patient and, more particularly, for isolating such an apparatus from external disturbances.
The present invention is an improvement upon finger-ring sensors such as those described in U.S. Pat. No. 5,964,701, issued Oct. 12, 1999, which incorporated herein by reference.
One of the most difficult problems in implementing a sensor that may be worn on the body is the issue of eliminating signal artifacts due to motion of, or forces exerted upon, the sensor. A further problem is the inflexibility of preprogrammed operating protocols.
In accordance with preferred embodiment of the invention, there is provided a monitoring system for monitoring the health status of a patient. The monitoring system has an inner ring characterized by a first mass. The inner ring is proximate to a finger of the patient and has at least one sensor coupled to the inner ring for providing a signal based on at least one of skin temperature, blood flow, blood constituent concentration, and pulse rate of the patient. The monitoring system also has an outer ring characterized by a second mass. The outer ring is coupled to the finger of the patient. The monitoring system has an electronics module disposed on the outer ring for processing the signal provided by the sensor and a flexible electrical coupling for conveying the signal from the sensor to the electronics module in such a manner as to maintain mechanical decoupling of the inner and outer rings.
In accordance with further embodiments of the invention, the pressure of the inner ring against the finger of the patient may be adjustable within a specified range, including by means of a material having a stiffness that is a nonlinear function of extension. The monitoring system may also have a light source and a detector for monitoring a characteristic of arterial blood flow within the finger, and a control loop for regulating the intensity of light emitted by the light source. Regulation may be in response to a ratio of signal to noise in the detector or to a signal generated by the temperature sensor.
In accordance with yet further embodiments of the invention, a health monitoring system may be provided that has at least one sensor coupled to a ring proximate to a finger of the patient for providing a signal based on at least one of skin temperature, blood flow, blood constituent concentration, and pulse rate of the patient, and an electronics module disposed on the ring for processing the signal provided by the sensor, wherein the electronic module includes a protocol scheduler for specifying a schedule of physiological measurements. The monitoring system may have a transponder for transmitting physiological data based on the sensor signal to a remote station unit and a receiver for receiving protocol scheduling commands from the remote station unit.